Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stanford researchers study how gene level variations in blood affect immunity

13.02.2003


Differences in people seem to run in the blood, according to a recent study that examines which genes are active in blood cells. The work, published in this week’s online issue of the Proceedings of the National Academy of Sciences, found that the levels of several genes used by blood cells vary from person to person.



"Nobody had taken this broad a look at genetic variation in the blood of healthy people," said David Relman, MD, associate professor of medicine at Stanford and a co-author of the study.

People vary greatly in their reactions to bacteria and viruses; some individuals fall prey to every bug that comes along while others go through winter sniffle-free. Relman, along with Patrick Brown, PhD, professor of biochemistry, and research assistant Adeline Whitney thought these differences might show up when looking at which genes are active in circulating blood cells.


To find out the extent and nature of the differences in gene activity in people’s blood, Relman and his colleagues drew blood from 75 healthy people and extracted a molecule called RNA. RNA is produced by active genes and can be used to identify which genes are being expressed in a given sample. They then attached a fluorescent molecule to the RNA and applied the samples to a gene chip - a glass slide dotted with human genes. If a sample contained RNA corresponding to a gene on the chip, the fluorescently labeled RNA would bind to the spot and produce a visible signal. The bigger the signal, the more RNA was present, and therefore the greater the gene expression. Whitney then compared which spots varied in brightness among the samples.

The blood used in this analysis contained a variety of cells, including red blood cells that carry oxygen to the tissues and immune cells that fight disease. The red blood cells don’t contain nuclei and therefore don’t produce RNA. That leaves immune cells as the only cells making RNA in the blood sample. Any differences found in the pattern of active genes resulted from these disease-fighting cells.

A few genes stood out as being used at varying levels in different people. Some of these could be used to distinguish between men and women. For example, women use different levels of genes whose proteins respond to an immune protein called interferon. Researchers had suspected that genes in the interferon pathway might have a role in the higher risk of autoimmune diseases among women.

The researchers also found variations in two genes that weren’t previously documented as being active in blood cells. One is a gene that makes the prion protein - the protein altered in people who have Creutzfeldt-Jakob disease. Another surprisingly variable gene was BRCA1, which is mutated in an inherited form of breast cancer. It could turn out that levels of the prion protein or BRCA1 in the blood play some role in determining the risk for prion-related diseases or cancer.

In addition to the variation of gene expression among different people, the researchers found genes that varied according to the time of day that blood was drawn. Other genes were used at higher or lower levels depending upon the age of the blood donor - a finding that could eventually help doctors understand why older people are more prone to some illnesses.

Relman pointed out that it’s too early to know why people use genes at higher or lower levels in blood cells, and the consequences of this variability. "It may be that some people confronted a virus or had a cold the week before, or had different environmental experiences," he said.

He added that despite the differences, there was remarkable similarity in the genes used in the blood cells among the study subjects. "It was surprising that the degree of variability was as small as it turns out to be," he said. This finding bodes well for using gene expression in blood to distinguish between healthy people and those with an infectious disease. Because people are usually quite similar, any disease-related variation should stand out.


Other Stanford researchers who contributed to the paper include MD/PhD students Maximillian Diehn, PhD, and Ash Alizadeh, PhD; postdoctoral fellow Stephen Popper, DSc; and medical student Jennifer Boldrick.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children’s Hospital at Stanford. For more information, please visit the Web site of the medical center’s Office of Communication & Public Affairs at http://mednews.stanford.edu.

PRINT MEDIA CONTACTS: Amy Adams at (650) 723-3900 (amyadams@stanford.edu)
BROADCAST MEDIA CONTACT: Neale Mulligan at (650) 724-2454 (nealem@stanford.edu)

Neale Mulligan | EurekAlert!
Further information:
http://med-www.stanford.edu/MedCenter/MedSchool/

More articles from Health and Medicine:

nachricht Cystic fibrosis alters the structure of mucus in airways
29.06.2017 | University of Iowa Health Care

nachricht Mice provide insight into genetics of autism spectrum disorders
28.06.2017 | University of California - Davis

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making Waves

Computer scientists use wave packet theory to develop realistic, detailed water wave simulations in real time. Their results will be presented at this year’s SIGGRAPH conference.

Think about the last time you were at a lake, river, or the ocean. Remember the ripples of the water, the waves crashing against the rocks, the wake following...

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Nanostructures taste the rainbow

29.06.2017 | Physics and Astronomy

New technique unveils 'matrix' inside tissues and tumors

29.06.2017 | Life Sciences

Cystic fibrosis alters the structure of mucus in airways

29.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>